Glucose oxidases are enzymes that catalyze the oxidation of glucose with oxygen whereby D-gluconic acid and hydrogen peroxide are formed. Such enzymes are known from microbial, plant and animal origins, e.g., glucose oxidase from Aspergillus, Penicillium and Talaromyces. Glucose oxidase has been described as useful for various purposes, e.g., for bleaching purposes and in the baking industry, useful for strengthening the dough.
An example of a commercial glucose oxidase is Gluzyme.TM., an Aspergillus niger glucose oxidase, available from Novo Nordisk A/S. The glucose oxidase from A. niger has been reported to have a molecular weight of about 150,000 and an FAD content of 2 F AD/mole. This enzyme has been cloned and expressed in a recombinant nucleic acid system (U.S. Pat. No. 5,094,951). This and similar products from other commercial sources have an acidic pH optimum, typically around pH 5, which means that they are not very active in detergent solutions or in baking due to the alkaline character of the detergents and baking processes.
A glucose oxidase with a neutral pH optimum has been isolated from strains of Cladosporium (WO 95/29996). This property makes the glucose oxidase particularly effective in detergent applications and in baking processes. However, no significant amino acid sequence analysis nor recombinant production of this enzyme has been accomplished. It would be advantageous to be able to isolate large quantities of such a glucose oxidase. Such a goal may be accomplished via recombinant methods of production.